Integrated circuits and integrated circuit systems can be found in a multitude of electronic devices, such as smart phones, digital cameras, location based devices, portable music players, printers, computers, etc. Some of the many challenges faced by the integrated circuit industry in producing these integrated circuits include designing faster, more reliable, and higher-density circuits at a lower cost.
During operation, these integrated circuits can be exposed to extreme temperature environments and/or generate their own undesirable heat profile that can interfere with the operation of the device itself and/or proximately located integrated circuits. Unfortunately, as modern consumer electronics continue to shrink and operate at continually increasing frequencies, the heat generated by these devices continues to increase as well.
Typically, before an integrated circuit reaches a customer, the integrated circuit manufacturer conducts a series of tests to verify that the integrated circuit operates according to some specification. Accordingly, the electronics industry has developed operational testing procedures to evaluate the structural integrity and heat tolerance of these circuits. Generally, in order to perform operational testing in integrated circuits, the DUT (Device Under Test) can be exercised through a range of temperatures. The larger the temperature range, the more useful the testing becomes. For flash type integrated circuits, higher temperatures (>85° C.) accelerate device test time and wear to prove endurance and retention algorithms. For ASICs, higher temperatures can either test a device to determine if it can operate at a temperature higher than specified (i.e., for industrial and/or defense applications) or determine the device's operating margin.
Unfortunately, a problem arises when taking the device tester through these extreme temperature profiles (e.g., greater than 80° C. ambient), as permanent damage to the tester itself can occur. Typical test systems can include environmental chambers, which house the entire test fixture, forced air systems with a custom hood, or automatic test equipment (ATE) with special ovens and heating fixtures.
Environmental chambers are costly options that consume large amounts of bench space and electricity. Environmental chambers also suffer from significant temperature variation between the PID (Proportional-Integral-Derivative) loop thermocouple and the DUT case temperature. Additionally, the maximum temperature of this system is limited to the maximum operating temperature of the tester components (typically 70° C. to 85° C.). Furthermore, the ramp rate of an environmental chamber is usually limited to avoid damage to the solder connections.
Forced-air systems share similar issues with environmental chambers while also possessing the additional burden of greater expense, complicated hoods, and substantial operating costs due to clean, dry air requirements. Moreover, a typical forced-air setup usually manages only four (4) devices depending on the air supply.
Although, ATE systems can be used for high temperature testing, ATE systems are extremely expensive and generally only accommodate between one (1) to four (4) devices at a time and are not intended for extended duration tests.
Thus, a need still remains for a reliable test system and method of fabrication, wherein the test system provides a cost effective high temperature testing procedure for electronic devices. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.